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Finding the Fourth Proportional to 666.91, 999.95 and 393.06

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Solution

The fourth proportional to 666.91, 999.95 and 393.06 is: 589.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.91 : 999.95 = 393.06 : x
  2. Step 2: Convert to fraction form
    666.91/999.95 = 393.06/x
  3. Step 3: Cross multiply
    666.91x = 999.95 × 393.06
  4. Step 4: Simplify right side
    666.91x = 393,041.33
  5. Step 5: Solve for x
    x = 393,041.33/666.91
  6. Step 6: Final answer
    x = 589.35

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.